Current Photovoltaic Research

Korea Photovoltaic Society (한국태양광발전학회)
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Characterization of an In2Se3 Passivation Layer for CIGS Solar Cells with Cd-free Zn-containing Atomic-layer-deposited Buffers

  • Kim, Suncheul (Department of Material Science and Engineering, Korea Advanced Institute of Science and Technology) ;
  • Lee, Ho Jin (Department of Material Science and Engineering, Korea Advanced Institute of Science and Technology) ;
  • Ahn, Byung Tae (Department of Material Science and Engineering, Korea Advanced Institute of Science and Technology) ;
  • Shin, Dong Hyeop (Photovoltaic Team, Korea Institute of Energy Research) ;
  • Kim, Kihwan (Photovoltaic Team, Korea Institute of Energy Research) ;
  • Yun, Jae Ho (Photovoltaic Team, Korea Institute of Energy Research)
  • Received : 2021.07.26
  • Accepted : 2021.09.09
  • Published : 2021.09.30
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Abstract

Even though above 22% efficiencies have been reported in Cd-free Cu(In,Ga)Se2 (CIGS) solar cell with Zn-containing buffers, the efficiencies with Zn-containing buffers, in general, are well below 20%. One of the reasons is Zn diffusion from the Zn-containing buffer layer to CIGS film during buffer growth. To avoid the degradation, it is necessary to prevent the diffusion of Zn atoms from Zn-containing buffer to CIGS film. For the purpose, we characterized an In2Se3 film as a possible diffusion barrier layer because In2Se3 has no Zn component. It was found that an In2Se3 layer grown at 300℃ was very effective in preventing Zn diffusion from a Zn-containing buffer. Also, the In2Se3 had a large potential barrier in the valence band at the In2Se3/CIGS interface. Therefore, In2Se3 passivation has the potential to achieve a super-high efficiency in CIGS solar cells that employ Cd-free ALD processed buffers containing Zn.

Keywords

Acknowledgement

This work was financially supported by the Technology Development Program to Solve Climate Change of the National Research Foundation of Korea (No. 2016M1A2A2936757) and by the Korea Institute of Energy Technology Evaluation and Planning (No.20163030013690).

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